An electric power system comprises an utility power grid connected to a first switch; and a microgrid connected to the utility power grid through the first switch, the microgrid comprising: inverter devices connected to a bus; a controller connected to the first switch and the inverter devices, and configured to transmit first signals; and loads connected to the inverter devices through the bus, wherein the utility power grid is connected to the bus through the first switch, and is configured to provide power to the loads, the controller is further configured to detect a first lane connecting the utility power grid with the microgrid and determine whether the first lane is abnormal, and when the first lane is abnormal, the controller cuts off the first switch, and switches a first part of the inverter devices to a voltage source configuration through the first signals.
Legal claims defining the scope of protection, as filed with the USPTO.
an utility power grid connected to a first switch; and a plurality of inverter devices connected to a bus; a controller connected to the first switch and each of the plurality of inverter devices, and configured to transmit a plurality of first signals; and a plurality of loads connected to the plurality of inverter devices through the bus, a microgrid connected to the utility power grid through the first switch, the microgrid comprising: wherein the utility power grid is connected to the bus through the first switch, and is configured to provide power to the plurality of loads, the controller is further configured to detect a first lane connecting the utility power grid with the microgrid, and determine whether the first lane is abnormal, and when the controller determines the first lane is abnormal, the controller cuts off the first switch, and switches a first part of the plurality of inverter devices to a voltage source configuration through the plurality of first signals. . An electric power system, comprising:
claim 1 when the controller determining the first lane is normal, the first switch remains thrown in, and each of the plurality of inverter devices operates under a current source configuration being different from the voltage source configuration, and when the controller determining the first lane is abnormal, a second part of the plurality of inverter devices operates under the current source configuration, and the second part is different from the first part. . The electric power system of, wherein
claim 2 a plurality of power converters connected to the bus; and a plurality of energy storage systems, respectively connected to the plurality of power converters, wherein when the first part of the plurality of inverter devices is operating under the voltage source configuration, the plurality of energy storage systems corresponding to the first part of the plurality of power converters is configured to provide power to the plurality of loads. . The electric power system of, wherein the plurality of inverter devices comprising:
claim 2 calculate a first capacity of the first part, when the first part of the plurality of inverter devices is operating under the voltage source configuration, and calculate a second capacity of the second part, when the second part of the plurality of inverter devices is operating under the current source configuration. . The electric power system of, wherein the controller is further configured to:
claim 4 when the first capacity is larger than a third capacity of the plurality of loads, the first part of the plurality of inverter devices is configured to provide power to each of the plurality of loads, when the first capacity is smaller than the third capacity, and the first capacity is larger than a fourth capacity of a third part of the plurality of loads, the first part and the second part of the plurality of inverter devices is configured to provide power to the fourth capacity of the plurality of loads, and when the fourth capacity changes, the first part of the plurality of inverter devices is configured to absorb the change of the fourth capacity, and when the first capacity is smaller than the fourth capacity, and when a sum of the first capacity and the second capacity is larger than the fourth capacity, each of the first part and the second part of the plurality of inverter devices is configured to provide power to the third capacity of the plurality of loads. . The electric power system of, wherein
claim 4 when a voltage level of a voltage of the first switch is lower than a lower limit voltage level, or higher than an upper limit voltage, the controller determining the first lane is abnormal, and when the first part of the plurality of inverter devices is switched to the voltage source configuration, each of the first part of the plurality of inverter devices transmits a plurality of state parameters to the controller, the plurality of state parameters at least comprises an output voltage of each of the first part of the plurality of inverter devices. . The electric power system of, wherein
claim 2 a plurality of inverters connected to the bus; and a plurality of renewable energy devices, respectively connected to the plurality of inverters, wherein when the first part of the plurality of inverter devices is operating under the voltage source configuration, the plurality of renewable energy devices corresponding to the first part of the plurality of inverters is configured to provide power to the plurality of loads. . The electric power system of, wherein the plurality of inverter devices further comprising:
claim 1 . The electric power system of, wherein the plurality of first signals are transmitted to the plurality of inverter devices by a GOOSE (Generic Object Oriented Substation Event) virtual channel communication technology.
connecting an utility power grid to a plurality of microgrids respectively through a plurality of lanes by a plurality of switches; detecting a plurality of voltages of the plurality of switches, and determining whether the plurality of lanes are abnormal according to the plurality of voltages; when determining a first lane of the plurality of lanes is abnormal, cutting off a first switch of the plurality of switches, and switching a first part of a plurality of inverter devices in a first microgrid of the plurality of microgrids to a voltage source configuration; and when determining the first lane is normal, remained throwing in the first switch, and each of the plurality of inverter devices operates under a current source configuration being different from the voltage source configuration, wherein when determining the first lane is abnormal, a second part the plurality of inverter devices operate under the current source configuration, and the second part is different from the first part. . A method for operating an electrical power system, comprising:
claim 9 when determining a second lane of the plurality of lanes is abnormal, and the first lane is normal, cutting off a second switch of the plurality of switches, and switching a third part of a plurality of inverter devices in a second microgrid of the plurality of microgrid to the voltage source configuration; and when determining the second lane is normal, remained throwing in the second switch, and each of and the plurality of inverter devices operates under the current source configuration being different from the voltage source configuration, wherein when determining the second lane is abnormal, a fourth part of the plurality of inverter devices operate under the current source configuration, and the fourth part is different from each of the first part, the second part, and the third part, and when determining the second lane is abnormal and the first lane is normal, each of the first part and the second part of the plurality of inverter devices operates under the current source configuration. . The method of, further comprising:
claim 10 calculating a first capacity of the first part operating under the voltage source configuration, and a second capacity of the second part operating under the current source configuration; calculating a third capacity of the third part operating under the voltage source configuration, and a fourth capacity of the fourth part operating under the current source configuration, wherein when the first capacity is larger than a fifth capacity of a plurality of loads in the first microgrid, the first part is configured to provide power to each of the plurality of loads, when the third capacity smaller than a sixth capacity of a plurality of loads in the second microgrid, and the third capacity is larger than a seventh capacity of a seventh part of the plurality of loads in the second microgrid, each of the plurality of inverter devices is configured to provide power to each of the plurality of loads. . The method of, further comprising:
claim 11 when the third capacity is larger than the sixth capacity, the third part is configured to provide power to each of the plurality of loads in the second microgrid. . The method of, wherein
claim 12 when the seventh capacity changes, the third part of the plurality of inverter devices is configured to absorb changes of the seventh capacity, and when the third capacity is smaller than seventh capacity, and when a sum of the third capacity and the fourth capacity is larger than seventh capacity, each of the third part and the fourth part of the plurality of inverter devices is configured to provide power to the sixth capacity of the plurality of loads. . The method of, wherein
claim 10 the plurality of inverter devices comprises a plurality of inverters and a plurality of energy storage systems, when the first part is operating under the voltage source configuration, the plurality of energy storage systems corresponding to the first part of the plurality of inverter devices are configured to provide power to a plurality of loads in the first microgrid, and when the third part is operating under the voltage source configuration, the plurality of energy storage systems corresponding to the third part of the plurality of inverter devices are configured to provide power to a plurality of loads in the second microgrid. . The method of, wherein
claim 10 the plurality of inverter devices comprising a plurality of inverters and a plurality of renewable energy devices, when the first part is operating under the voltage source configuration, the plurality of renewable energy devices corresponding to the first part of the plurality of inverter devices are configured to provide power to a plurality of loads in the first microgrid, and when the third part is operating under the voltage source configuration, the plurality of renewable energy devices corresponding to the third part of the plurality of inverter devices are configured to provide power to a plurality of loads in the second microgrid. . The method of, wherein
claim 10 when a voltage level of a voltage of the first switch is lower than a lower limit voltage level, or higher than an upper limit voltage level, the first lane is determined to be abnormal, and when the first part is switched to the voltage source configuration, each of the first part of the plurality of inverter devices transmits a plurality of first state parameters to a first controller of the first microgrid, the plurality of first state parameters at least comprises an output voltage of each of the first part of the plurality of inverter devices. . The method of, wherein
claim 16 when a voltage level of a voltage of the second switch is lower than the lower limit voltage level, or higher than the upper limit voltage level, the second lane is determined to be abnormal, and when the third part is switched to the voltage source configuration, each of the third part the plurality of inverter devices transmit a plurality of second state parameters to a second controller of the second microgrid, the plurality of second state parameters at least comprises an output voltage of each of the third part of the plurality of inverter devices. . The method of, wherein
claim 17 the first controller switches the first part to the voltage source configuration through a plurality of first signals, the second controller switches the third part to the voltage source configuration through a plurality of second signals, and each of the plurality of first signals and the plurality of second signals is transmitted to the plurality of inverter devices by a GOOSE (Generic Object Oriented Substation Event) virtual channel communication technology. . The method of, wherein
claim 18 when the plurality of first state parameters are transmitted back to the first controller, the first controller determines whether the corresponding plurality of first state parameters is the same as the plurality of first signals, when the plurality of first state parameters is the same as the plurality of first signals, the first switch remains cut off, and the first part and the second part are configured to provide power to the plurality of loads of the first microgrid, and when the corresponding output voltage of the plurality of first state parameters is not the same as the plurality of first signals, the first controller performs a parameter compensation to the plurality of inverter devices in the first microgrid. . The method of, further comprising:
claim 19 when the plurality of second state parameters are transmitted back to the second controller, the second controller determines whether the corresponding plurality of second state parameters is the same as the plurality of second signals, when the plurality of second state parameters is the same as the plurality of second signals, the second switch remains cut off, and the third part and the fourth part are configured to provide power to the plurality of loads of the second microgrid, and when the corresponding output voltage of the plurality of second state parameters is not the same as the plurality of second signals, the second controller performs the parameter compensation to the plurality of inverter devices in the second microgrid. . The method of, further comprising:
Complete technical specification and implementation details from the patent document.
This application claims priority to China Application Serial Number 202511159135.7, filed on Aug. 19, 2025 and U.S. Provisional Application Ser. No. 63/745,800, filed on Jan. 16, 2025, which are herein incorporated by reference.
The present disclosure relates to an electric power system. More particularly, the present disclosure relates to an electric power system having multiple inverter devices with power mode switching functionality, and method of operating the same.
In the existing electric power system, the microgrid in the infrastructure combining microgrid with the local area network or utility power grid uses feeder lines to encompass the service region, and utility power grid provides electricity to the microgrid for powering the loads. When the utility power grid at the upstream of the feeder lines encounters abnormality, the loads can only be powered by the microgrid in islanded operation. Not until the abnormality is resolved would the reconnection to the utility power grid be recovered. At this moment, the power distribution and the powering capacity of the islanded microgrid require further consideration to obtain sufficient source of charges.
The present disclosure provides an electric power system. The electric power system comprises: an utility power grid connected to a first switch; and a microgrid connected to the utility power grid through the first switch, the microgrid comprising: a plurality of inverter devices connected to a bus; a controller connected to the first switch and each of the plurality of inverter devices, and configured to transmit a plurality of first signals; and a plurality of loads connected to the plurality of inverter devices through the bus, wherein the utility power grid is connected to the bus through the first switch, and is configured to provide power to the plurality of loads, the controller is further configured to detect a first lane connecting the utility power grid with the microgrid, and determine whether the first lane is abnormal, and when the controller determines the first lane is abnormal, the controller cuts off the first switch, and switches a first part of the plurality of inverter devices to a voltage source configuration through the plurality of first signals.
The present disclosure provides a method for operating an electrical power system. The method comprises: connecting an utility power grid to a plurality of microgrids respectively through a plurality of lanes by a plurality of switches; detecting a plurality of voltages of the plurality of switches, and determining whether the plurality of lanes are abnormal according to the plurality of voltages; when determining a first lane of the plurality of lanes is abnormal, cutting off a first switch of the plurality of switches, and switching a first part of a plurality of inverter devices in a first microgrid of the plurality of microgrids to a voltage source configuration; and when determining the first lane is normal, remained throwing in the first switch, and each of the plurality of inverter devices operates under a current source configuration being different from the voltage source configuration, wherein when determining the first lane is abnormal, a second part the plurality of inverter devices operate under the current source configuration, and the second part is different from the first part.
It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the disclosure as claimed.
In the present disclosure, when an element is referred to as “connected” or “coupled”, it may mean “electrically connected” or “electrically coupled”. “Connected” or “coupled” can also be used to indicate that two or more components operate or interact with each other. In addition, although the terms “first”, “second”, and the like are used in the present disclosure to describe different elements, the terms are used only to distinguish the elements or operations described in the same technical terms. The use of the term is not intended to be a limitation of the present disclosure.
Unless otherwise defined, all terms (including technical and scientific terms) used in the present disclosure have the same meaning as commonly understood by the ordinary skilled person to which the concept of the present invention belongs. It will be further understood that terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning consistent with its meaning in the related technology and/or the context of this specification and not it should be interpreted in an idealized or overly formal sense, unless it is clearly defined as such in this article.
The terms used in the present disclosure are only used for the purpose of describing specific embodiments and are not intended to limit the embodiments. As used in the present disclosure, the singular forms “a”, “one” and “the” are also intended to include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in this specification, the terms “comprises (comprising)” and/or “includes (including)” designate the existence of stated features, steps, operations, elements and/or components, but the existence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof are not excluded.
Hereinafter multiple embodiments of the present disclosure will be disclosed with schema, as clearly stated, the details in many practices it will be explained in the following description. It should be appreciated, however, that the details in these practices is not applied to limit the present disclosure. Also, it is to say, in some embodiments of the present disclosure, the details in these practices are non-essential. In addition, for the sake of simplifying schema, some known usual structures and element in the drawings by a manner of simply illustrating for it.
1 FIG. 1 FIG. 100 100 110 120 130 110 120 130 is a schematic diagram of an electric power system, illustrate in accordance with some embodiments of the present disclosure. As illustratively shown in, the electric power systemincludes a microgrid, a power distribution system, and a utility power grid. In some embodiments, the microgridis separated with the power distribution systemand the utility power gridthrough a point of common coupling (PCC) to divide into a utility side and a microgrid side.
1 FIG. 110 111 112 116 11 12 10 15 11 12 112 122 132 113 123 133 114 124 134 115 125 135 116 126 136 As illustratively shown in, the microgridincludes a controller, multiple inverter devices-, multiple loads Nand N, and multiple switches CB-CB, CBNand CBN. In some embodiments, the inverter deviceincludes a power converterand an energy storage system. The inverter deviceincludes a power converterand an energy storage system. The inverter deviceincludes an inverterand a renewable energy device. The inverter deviceincludes an inverterand a renewable energy device. The inverter deviceincludes an inverterand a renewable energy device.
1 FIG. 122 132 110 11 123 133 110 12 124 134 110 13 125 135 110 14 126 136 110 15 11 110 11 12 110 12 As illustratively shown in, the power converteris connected to the energy storage system, and connected to a bus BSthrough the switch CB. The power converteris connected to the energy storage system, and connected to a bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and connected to a bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and connected to a bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and connected to a bus BSthrough the switch CB. The load Nis connected to the bus BSthrough the switch CBN. The load Nis connected to the bus BSthrough the switch CBN.
130 120 120 10 1 10 110 110 111 10 10 10 3 FIG. In some embodiments, the utility power gridis connected to the power distribution system. The power distribution systemis connected to the switch CBthrough a lane L, and the switch CBis connected to the bus BSconfigured to distribute the electricity to the microgrid. The controlleris connected to the switch CB, and is configured to detect parameters on the utility side and control the throw in and cut off of the switch CB. Further details regarding the detection of the parameters on the utility side and the control of the switch CBare discussed inand the corresponding paragraphs of the present disclosure.
130 10 130 110 11 12 132 133 130 110 130 10 130 110 132 133 134 136 11 12 130 110 11 12 3 FIG. In some circumstances, when the utility power gridoperates normally, and the switch CBis thrown in, the utility power gridis configured to distribute electricity to the microgrid, and provides power to the loads Nand N, or charges the energy storage systemsand. The utility power gridis configured to provide power to the load, or charges the energy storage system according to the operation status of the microgrid. In some other circumstances, when the utility power gridoperates abnormally, and the switch CBis cut off, the utility power gridis disconnected with the microgrid, and the energy storage systemsandand the renewable energy devices-are configured to provide power to the loads Nand N. Further details regarding the determination of whether the utility power gridoperates normally or abnormally and the microgridthat provides power the loads Nand Nare discussed inand the corresponding paragraphs of the present disclosure.
130 112 116 112 116 112 116 122 123 124 126 130 In some embodiments, when the utility power gridis normal, each of the inverter devices-operates in the Grid-Following (GFL) operating mode. Specifically, when the inverter devices-are operating in GFL operating mode, the inverter devices-operate in current source configuration. At this moment, the power converters-and the inverters-operate based on the voltage and the frequency provided by the utility power grid.
130 110 112 116 112 116 112 116 122 123 124 126 11 12 10 110 130 110 11 12 In some embodiments, when the utility power gridis abnormally, or when the microgridis islanded operating, a part of the inverter devices-is switched to the Grid-Forming (GFM) operating mode. Specifically, when one or multiple inverter devices-are operating in GFM operating mode, the inverter devices-operate in voltage source configuration. At this moment, the power converters-and the inverters-generate the voltage and the frequency independently to provide power to each of the loads Nand N. In some embodiments, the term islanded indicates that when the switch CBconnecting the microgridand the utility power gridis cut off, the microgridoperates independently to provide power to each of the loads Nand N.
1 FIG. 111 112 116 1 5 112 116 111 112 116 1 5 1 5 111 1 5 122 123 124 126 1 5 As illustratively shown in, the controllercontrols the inverter devices-by signals S-Srespectively, and is configured to switch the operating mode of the inverter devices-. Specifically, the controllerswitches the inverter devices-from the GFL operating mode to the GFM operating mode, and/or from the GFM operating mode to the GFL operating mode through the signals S-S, respectively. In some embodiments, each of the signals S-Scan be implemented by optical fiber or control cable, and the controllertransmits the signals S-Srespectively to the power converters-and the inverters-through the virtual channels of power interoperability. In some embodiments of the present disclosure, the signals S-Scan be implemented by the virtual channels conformed to the communication technology of Generic Object Oriented Substation Event (GOOSE).
120 130 111 112 116 11 12 10 15 11 12 100 111 1 5 112 116 In some embodiments, each of the power distribution system, the utility power grid, the controller, the inverter devices-, the loads Nand N, and the switches CB-CB, CBNand CBNin the electric power systemis connected to each other through power lines. In some embodiments, the controllertransmits the signals S-Srespectively to the inverter devices-through the GOOSE communication lines.
11 15 11 12 110 11 15 11 12 In the embodiment of the present disclosure, each of the switches CB-CB, CBNand CBNis operated under thrown-in configuration. Alternatively stated, when the microgridis operating, each of the switches CB-CB, CBNand CBNis turned on.
112 116 122 123 132 133 124 126 134 136 134 136 In some embodiments, the inverter devices-can be implemented by the Inverters Base Resources (IBRs). The power converters-can be implemented by the Power Conversion System (PCS). The energy storage systems-can be implemented by the Battery Energy Storage System (BESS). The inverters-can be implemented by the Photovoltaic Inverter (PV Inverter). The renewable energy devices-can be implemented by the Photovoltaic Array (PV Array). In some embodiments, the renewable energy devices-can also be implemented by the power generators or the renewable energy sources, such as solar power system, wind power system, hydroelectric power system, and geothermal power system; however the present disclosure is not limited to the power systems mentioned above.
120 130 In some embodiments, the power distribution systemcan be located in the substation or associated facilities, and is configured to distribute the electricity provided by the utility power gridto multiple different microgrids.
11 12 11 12 In some embodiments, the loads N-Nare general electricity consumptions having a lower instantaneous load power. In some other embodiments, the loads N-Ncan be Electric Vehicle (EV) power consumptions having a higher instantaneous load power. For example, the general electricity consumptions could have 0.05-5.0 kilo watt per hour (kWh) of instantaneous load power, the EV power consumptions could have 20-400 kWh of instantaneous load power.
2 FIG. 2 FIG. 200 200 100 200 210 is a schematic diagram of an electric power system, illustrated in accordance with some embodiments of the present disclosure. As illustratively shown in, the electric power systemincludes all the components of the electric power system. The electric power systemfurther includes a microgrid.
200 100 100 200 110 210 In some embodiments, the electric power systemis another embodiment of the electric power system. In various embodiments, the electric power systemsandmay include one or more microgrids, such as the microgridsand, but the present disclosure is not limited to this.
2 FIG. 210 211 212 216 21 22 20 25 21 22 212 222 232 213 223 233 214 224 234 215 225 235 216 226 236 210 110 210 110 As illustratively shown in, the microgridincludes a controller, multiple inverter devices-, multiple loads Nand N, and multiple switches CB-CB, CBNand CBN. In some embodiments, the inverter deviceincludes a power converterand an energy storage system. the inverter deviceincludes a power converterand an energy storage system. The inverter deviceincludes an inverterand a renewable energy device. The inverter deviceincludes an inverterand a renewable energy device. The inverter deviceincludes an inverterand a renewable energy device. In some embodiments, the connecting relationship between various components in the microgridand the operating method are similar to the microgrid. The similarities between the microgridsandare not repeated herein for simplicity.
2 FIG. 222 232 210 21 223 233 210 22 224 234 210 22 225 235 210 22 226 236 210 22 21 210 21 22 210 22 As illustratively shown in, the power converteris connected to the energy storage system, and is connected to the bus BSthrough the switch CB. The power converteris connected to the energy storage system, and is connected to the bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and is connected to the bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and is connected to the bus BSthrough the switch CB. The inverteris connected to the renewable energy device, and is connected to the bus BSthrough the switch CB. The load Nis connected to the bus BSthrough the switch CBN. The load Nis connected to the bus BSthrough the switch CBN.
120 20 2 20 210 210 211 20 20 20 210 110 210 110 3 FIG. In some embodiments, the power distribution systemis connected to the switch CBthrough the lane L, and the switch CBis connected to the bus BSconfigured to distribute the electricity to the microgrid. The controlleris connected to the switch CB, and is configured to detect parameters on the utility side and control the throw in and cut off of the switch CB. Further details regarding the detection of the parameters on the utility side and the control of the switch CBare discussed inand the corresponding paragraphs of the present disclosure. In some embodiments, the independent operation of the microgridis similar to the microgrid. Therefore, the similarities between the operation of the microgridsandare not discussed herein for simplicity.
130 10 20 130 110 210 11 12 21 22 In some circumstances, when the utility power gridoperates normally, and each of the switches CBand CBis thrown in, the utility power gridis configured to distribute the electricity to each of the microgridsand, and is configured to provide power to the loads N, N, N, and N.
130 10 20 130 110 210 132 133 134 136 11 12 232 233 234 236 21 22 In some other circumstances, when the utility power gridoperates abnormally, and each of the switches CBand CBis cut off, the utility power gridis disconnected with each of the microgridsand. The energy storage systemsandand the renewable energy devices-are configured to provide power to the loads Nand N. The energy storage systemsandand the renewable energy device-are configured to provide power to the loads Nand N.
130 10 20 10 20 10 20 130 130 10 20 130 210 21 22 130 110 110 132 133 134 136 11 12 In yet some other circumstances, when the utility power gridoperates normally, and one of the switches CBand CBis cut off, the microgrid, corresponding to the switches CBand CBthat has been cut off, is islanded. The electricity is provided to the microgrid, corresponding to the switches CBand CBthat has not been cut off, by the utility power grid. For example, when the utility power gridoperates normally, the switch CBis cut off, and the switch CBis thrown in, the utility power gridis configured to distribute electricity to the microgrid, configured to provide power to the loads Nand N. In the meantime, the utility power gridis disconnected with the microgrid, such that the microgridis islanded. The energy storage systemsandand the renewable energy devices-are configured to provide power to the loads Nand N.
2 FIG. 211 212 216 6 10 212 216 211 212 216 6 10 6 10 As illustratively shown in, the controllercontrols the inverter devices-respectively through the signals S-S, and is configured to switch the operating mode of the inverter devices-. Specifically, the controllerswitches the inverter devices-from the GFL operating mode to the GFM operating mode, and/or from the GFM operating mode to the GFL operating mode respectively through the signals S-S. In some embodiments, the signals S-Scan be implemented by the virtual channels conformed to the communication technology of GOOSE.
130 112 116 212 216 112 116 212 216 In some embodiments, when the utility power gridis operating normally, each of the inverter devices-and-is operating under the GFL operating mode. At this moment, each of the inverter devices-and-operate in current source configuration.
130 112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 In some other embodiments, when the utility power gridis operating abnormally, a part of the inverter devices-and-is switched to the GFM operating mode. At this moment, the inverter devices-and-operate in voltage source configuration. In some embodiments, a part of the inverter devices-and-includes one or more of the inverter devices-, and/or one or more of the inverter devices-.
211 212 216 21 22 20 25 21 22 211 6 10 212 216 In some embodiments, each of the controller, the inverter devices-, the loads Nand N, and the switches CB-CB, CBNand CBNis connected to each other through the power line. In some embodiments, the controllertransmits the signals S-Sto the inverter devices-respectively through the GOOSE communication line.
21 25 21 22 210 21 25 21 12 In the embodiment of the present disclosure, each of the switches CB-CB, CBNand CBNis operated under thrown-in configuration. Alternatively stated, when the microgridis operating, each of the switches CB-CB, CBNand CBNis turned on.
212 216 222 223 232 233 224 226 234 236 In some embodiments, the inverter devices-can be implemented by the IBRs. The power converters-can be implemented by the PCS. The energy storage systems-can be implemented by the BESS. The inverters-can be implemented by the PV inverter. The renewable energy devices-can be implemented by the PV array.
21 22 21 22 In some embodiments, the loads N-Nare general electricity consumptions having a lower instantaneous load power. In some other embodiments, the loads N-Ncan be Electric Vehicle (EV) power consumptions having a higher instantaneous load power.
3 FIG. 3 FIG. 300 100 200 300 301 312 300 100 200 200 300 is a flowchart diagram of an operating methodfor operating an electric power systemor, illustrated in accordance with some embodiments of the present disclosure. As illustratively shown in, the operation methodincludes operations-. In some embodiments, the operation methodcan be applied to the electric power systemsand. The following embodiments are discussed with the electric power systemhereafter to illustrate the operation method.
301 200 130 110 210 In the operation, when the electric power systemis operating, each of the utility power gridand the microgridandare interconnected for operation.
200 110 210 10 20 130 110 210 120 11 12 21 22 200 302 301 Specifically, when the electric power systemis operating, the microgridand the microgridthrow in the switches CBand CB, respectively. At this moment, the utility power griddistributes the electricity to each of the microgridand the microgridthrough the power distribution systemto provide power to the loads N, N, Nand N. The electric power systemperforms the operationafter the operationis performed.
302 111 211 1 2 In the operation, the controllersandperform measurement to the lanes Land Lrespectively, and calculate parameters on the utility side.
111 120 10 1 211 120 20 2 10 20 10 20 10 20 10 120 20 120 Specifically, the controllermeasures multiple parameters between the power distribution systemand the switch CBthrough the lane L. The controllermeasures multiple parameters between the power distribution systemand the switch CBthrough the lane L. The multiple parameters include voltages V_CBand V_CB, currents I_CBand I_CB, and frequencies F_CBand F_CBrespectively between the switch CBand the power distribution systemand between the switch CBand the power distribution system. However, the present disclosure is not limited to these parameters mentioned above.
111 211 1 2 200 303 302 In some embodiments, the controllersandcan measure the parameters of the lanes Land Lthrough the relay and the voltmeter. The electric power systemperforms the operationafter the operationis performed.
303 111 211 112 116 212 216 In the operation, the controllersandrespectively monitor multiple initial state parameters of the inverter devices-and-.
112 116 111 1 5 212 216 211 6 10 Specifically, the inverter devices-transmit the corresponding initial state parameters to the controllerthrough the signals S-S. The inverter devices-transmit the corresponding initial state parameters to the controllerthrough the signals S-S.
112 116 112 116 112 116 112 116 212 216 212 216 212 216 212 216 112 116 212 216 200 304 303 In some embodiments, the initial state parameters of the inverter devices-include the operation status of the inverter devices-and the energy capacities S_GFL-S_GFL of the inverter devices-operating under the GFL operating mode. The initial state parameters of the inverter devices-include the operation status of the inverter devices-and the energy capacities S_GFL-S_GFL of the inverter devices-operating under the GFL operating mode. In some embodiments, each of the energy capacities S_GFL-S_GFL and S_GFL-S_GFL has a unit of kilowatt per hour (kWh) or megawatt per hour (MWh). The electric power systemperforms the operationafter the operationis performed.
304 111 211 110 210 In the operation, the controllersandrespectively calculate the total energy capacity of the microgridsand.
111 1 110 112 116 112 116 211 2 210 212 216 212 216 Specifically, the controllercalculates the total energy capacity ST_GFL of the microgrid, when the inverter devices-are operating under the GFL operating mode, and when the inverter devices-are operating under the GFM operating mode. Similarly, the controllercalculates the total energy capacity ST_GF of the microgrid, when the inverter devices-are operating under the GFL operating mode, and when the inverter devices-are operating under the GFM operating mode.
1 2 In some embodiments, the total energy capacities ST_GFL and ST_GFL are calculated according to the following equation.
Wherein Ni, Nj, i and j are positive integers being larger than zero.
1 2 In the equation (1), the total energy capacity ST_GFL (t) is configured to indicate the total energy capacity of the microgrid operating under the GFL operating mode at the time t, such as the total energy capacities ST_GFL and ST_GFL.
112 113 112 113 In the equation (1), the energy capacity S_PCS_GFL_i (t) is configured to indicate the total energy capacity of the inverter devices, which are implemented by PCS, operating under the GFL operating mode at the time t. Wherein the integer Ni is configured to indicate a quantity of the inverter devices being implemented by the PCS in the microgrid, such as the inverter devicesand. The integer i is configured to indicate the i-th inverter device being implemented by the PCS. For example, the integer i being equal to 1 indicates the inverter device, and the integer i being equal to 2 indicates the inverter device.
114 116 114 115 116 In the equation (1), the energy capacity S_PV_GFL_j (t) is configured to indicate the total energy capacity of the inverter devices, which are implemented by inverters, operating under the GFL operating mode at the time t. Wherein the integer Nj is configured to indicate a quantity of the inverter devices being implemented by the inverters, such as the inverter devices-. The integer j is configured to indicate the j-th inverter devices being implemented by the inverters. For example, the integer j being equal to 1 indicates the inverter device, the integer j being equal to 2 indicates the inverter device, and the integer j being equal to 3 indicates the inverter device. In some embodiments, the energy capacity S_PV_GFL_j is configured to indicate the energy capacity of the PV inverter.
In some embodiments, the parameter B_j (t) in the equation (1) is configured to indicate a percentage of maximum power point (MPP) of the j-th PV inverter at the time t. In some embodiments, the parameter B_j is represented by percentage or decimal point, such as 20% or 0.2. However, the present disclosure is not limited to these representation and values.
1 2 1 2 1 2 In some embodiments, the energy capacities S_GFM and S_GFM are calculated according to the total energy capacities ST_GFL and ST_GFL. Specifically, the energy capacities S_GFM and S_GFM are calculated by the following equation.
1 2 In the equation (2), the energy capacity S_GFM (t) is configured to indicate the energy capacity of the microgrid operating under the GFM operating mode at the time t, such as the total energy capacities S_GFM and S_GFM.
In some embodiments, the parameter A (t) is configured to indicate a convertibility percentage of the multiple inverter devices switching from the GFL operating mode to the GFM operating mode. In some embodiments, the parameter A is represented by percentage or decimal point, such as 20% or 0.2. However, the present disclosure is not limited to these representation and values.
In some embodiments, the percentage value of the parameter A is proportional to a quantity of the inverter devices operating under the GFM operating mode. Specifically, when the quantity of the inverter devices that are switched from the GFL operating mode to the GFM operating mode is increased, the percentage value of the parameter A increases. When the quantity of the inverter devices that are switched from the GFL operating mode to the GFM operating mode is decreased, the percentage value of the parameter A decreases.
112 116 1 110 112 116 1 110 112 116 1 110 For example, in the equation (2), when each of the inverter devices-is operating under the GFL operating mode, the total energy capacity ST_GFL of the microgridhas 50 MWh. In some circumstances, when one of the inverter devices-is switching from the GFL operating mode to the GFM operating mode, the parameter A has the convertibility percentage 20%. At this moment, the energy capacity S_GFM of the microgridis equal to 50 MWh multiplied by 20%, which is 10 MWh. In some other circumstances, when more than one of the inverter devices-are switching from the GFL operating mode to the GFM operating mode, the parameter A has the convertibility percentage 90%. At this moment, the energy capacity S_GFM of the microgridis equal to 50 MWh multiplied by 90%, which is 45 MWh.
2 2 210 212 216 2 2 110 2 2 200 305 304 In some embodiments, the calculation of the total energy capacity ST_GFL and the energy capacity S_GFM of the microgrid, and the relationship between the operating mode of the inverter devices-with the total energy capacity ST_GFL and energy capacity S_GFM are similar to the microgrid. The calculation of the total energy capacity ST_GFL and the energy capacity S_GFM are not repeated herein for simplicity. The electric power systemperforms the operationafter the operationis performed.
305 111 211 112 116 212 216 In the operation, the controllersandrespectively calculate total state of charges when the inverter devices-and-are operating under the GFM operating mode and the GFL operating mode.
111 1 112 116 1 112 116 211 2 212 216 2 212 216 Specifically, the controllercalculates the energy capacity S_GFM of which a part of the inverter devices-is operating under the GFM operating mode, and the energy capacity S_GFL of which the other part of the inverter devices-remains operating under the GFL operating mode. The controllercalculates the energy capacity S_GFM of which a part of the inverter devices-is operating under the GFM operating mode, and the energy capacity S_GFL of which the other part of the inverter devices-remains operating under the GFL operating mode.
1 2 1 2 In some embodiments, the energy capacities S_GFM and S_GFM are calculated through the equation (2). The energy capacities S_GFL and S_GFL can be calculated by the following equation.
1 2 In the equation (3), the energy capacity S_GFL (t) is configured to indicate the energy capacity of the microgrid when one or more of the inverter devices remain operating under the GFL operating mode at time t, such as the energy capacities S_GFL and S_GFL.
In some embodiments, the operating mode of the multiple inverter devices can be switched according to the load capacity S_Load of the loads. Specifically, when a part of the inverter devices is operating under the GFL operating mode, the microgrid has the energy capacity S_GFL. When the other part of the inverter devices is operating under the GFM operating mode, the microgrid has the energy capacity S_GFM. At this moment, the sum of the energy capacities S_GFL and S_GFM is required to be larger than or equal to the load capacity S_Load, and satisfies the following equation.
As illustratively shown in the equation (4), the sum of the energy capacities S_GFL and S_GFM at time t is larger than or equal to the load capacity S_Load required by the loads at time t.
11 12 11 12 112 116 112 116 110 1 1 1 1 11 12 210 110 210 For example, the loads Nand Nhave the load capacities S_Nand S_Nrespectively at time t. When a part of the inverter devices-is operating under the GFL operating mode, and the other part of the inverter devices-is operating under the GFM operating mode, the microgridhas the energy capacities S_GFL and S_GFM. At this moment, the sum of each of the energy capacities S_GFL and S_GFM is requited to be larger than or equal to the sum of each of the loads capacities S_Nand S_N. The operation of the microgridis similar to the operation of the microgrid, and thus the discussion regarding the load capacity of the microgridis not repeated herein for simplicity.
In some embodiments, a part of the loads can further be categorized into essential loads, and the other part of the loads can further be categorized into non-essential loads. Correspondingly, the load capacity S_Load can further be categorized into an essential load capacity SC_Load of the essential loads and a non-essential load capacity SNC_Load of the non-essential loads, and satisfies the following equation.
As illustratively shown in the equation (5), the load capacity S_Load required by the loads in the microgrid at time t is equal to the sum of each of the essential load capacity SC_Load and the non-essential the load capacity SNC_Load.
110 210 11 12 21 22 11 21 11 12 21 22 12 22 For example, in the microgridsand, a part of the loads N, N, Nand Ncan be essential loads, such as the loads Nand N. The other part of the loads N, N, Nand Ncan be non-essential loads, such as the loads Nand N. However, the present disclosure is not limited to this example.
200 306 305 In some embodiments, the essential load capacity SC_Load is configured to indicate the load capacity required by the essential loads. The essential loads may include hospital, city hall, military facilities, banks or other similar electrical facilities, but the present disclosure is not limited to above mentioned essential facilities. The non-essential load capacity SNC_Load is configured to indicate the load capacity required by the non-essential loads. The non-essential loads may include general residential electricity, charging station or other similar electrical facilities, but the present disclosure is not limited to above mentioned non-essential facilities. The electric power systemperforms the operationafter the operationis performed.
306 111 211 130 1 2 130 In the operation, the controllersanddetermine whether the utility power gridand the lanes Land Lconnecting to the utility power gridare abnormal.
111 1 10 10 10 211 2 20 20 20 Specifically, the controllerdetermines whether the lane Lis abnormal according to the voltage V_CB, the current I_CBand the frequency F_CB. Similarly, the controllerdetermines whether the lane Lis abnormal according to the voltage V_CB, the current I_CBand the frequency F_CB.
10 10 111 1 10 111 1 10 10 111 1 In some embodiments, when the voltage level of the voltage V_CBis lower than or equal to a lower limit voltage level V_limL, or when the voltage level of the voltage V_CBis higher than or equal to an upper limit voltage level V_limH, the controllerdetermining the lane Lis abnormal. When the current level of the current I_CBis higher than a critical current level I_lim, the controllerdetermining the lane Lis abnormal. When the frequency F_CBlower than or equal to a lower limit frequency F_limL, or when the frequency F_CBis higher than or equal to an upper limit frequency F_limH, the controllerdetermining the lane Lis abnormal.
20 20 211 2 20 211 2 20 20 211 2 Correspondingly, when the voltage level of the voltage V_CBis lower than or equal to the lower limit voltage level V_limL, or when the voltage level of the voltage V_CBis higher than or equal to the upper limit voltage level V_limH, the controllerdetermining the lane Lis abnormal. When the current level of the current I_CBis higher than the critical current level I_lim, the controllerdetermining the lane Lis abnormal. When the frequency F_CBlower than or equal to the lower limit frequency F_limL, or when the frequency F_CBis higher than or equal to the upper limit frequency F_limH, the controllerdetermining the lane Lis abnormal.
111 211 1 2 111 211 130 200 307 306 In some embodiments, when the controllersandrespectively determine the lanes Land Lare abnormal, the controllersanddetermine the utility power gridis abnormal, and the electric power systemperforms the operationafter the operationis performed.
111 211 1 2 111 211 130 200 302 306 In some embodiments, when the controllersandrespectively determine the lanes Land Lare normal, the controllersanddetermine the utility power gridis normal, and the electric power systemrepeats the operationafter the operationis performed.
307 111 211 10 20 130 In the operation, the controllersandcut off the switches CBand CBconnecting to the utility power grid, and transmit commands to the inverter devices.
111 211 10 20 130 110 210 111 112 116 1 5 211 212 216 6 10 Specifically, when the controllersandcut off the switches CBand CBconnecting to the utility power grid, the microgridsandare islanded operating. At this moment, the controllertransmits the commands to the inverter devices-respectively through the signals S-S. The controllertransmits the commands to the inverter devices-respectively through the signals S-S.
112 116 212 216 112 116 212 216 200 308 307 In some embodiments, the operation of the commands mentioned above includes switching the inverter devices-and-from the GFL operating mode to the GFM operating mode, and sets the voltages of the inverter devices-and-to the corresponding rated output voltage level V_DEF. However, the commands may include other similar parameters and settings; the present disclosure is not limited to the commands mentioned above. The electric power systemperforms the operationafter the operationis performed.
308 111 211 In the operation, the controllersandswitch a part of the inverter devices to the GFM operating mode and the GFL operating mode.
111 112 116 1 5 211 212 216 6 10 Specifically, the controllerswitches one or more of the inverter devices-from the GFL operating mode to the GFM operating mode respectively through the signals S-S. The controllerswitches one or more of the inverter devices-from the GFL operating mode to the GFM operating mode respectively through the signals S-S.
1 110 1 11 12 2 210 2 21 22 In some embodiments, since the module and arrangement of the inverter devices are different, such that the energy capacities provided by the inverter devices operating under the GFM operating mode are different. Therefore, the energy capacity S_GFM that the microgrid can provide to the loads is different. For example, in some circumstances, the energy capacity S_GFM that the microgridcan provide under the GFM operating mode is smaller than the load capacity S_Load required by the loads Nand N. In some other circumstances, the energy capacity S_GFM that the microgridcan provide under the GFM operating mode is larger than the load capacity S_Load required by the loads Nand N.
111 211 112 116 212 216 11 12 21 22 In the circumstance mentioned above, the disclosed controllersandcan switch a part of the inverter devices-and-from the GFL operating mode to the GFM operating mode to provide power to the loads N, N, N, and Naccording to methods of a total load capacity determination, an essential load capacity provided under the GFM operating mode determination, and an essential load capacity provided under the GFL and the GFM operating modes determination.
In the method of the total load capacity determination, when the controller calculates that the energy capacity S_GFM is larger than the load capacity S_Load required by the loads, one or multiple inverter devices are switched to the GFM operating mode, and are configured to provide power to the loads. The method of the total load capacity determination satisfies the following equation.
Specifically, when the energy capacity S_GFM of the microgrid at time t is larger than the load capacity S_Load at time t, the energy capacity S_GFM of the inverter devices operating under the GFM operating mode can provide power to the loads in the microgrid. At this moment, the energy capacity S_GFL that the inverter devices operating under the GFL operating mode is equal to the total energy capacity ST_GFL subtracting the energy capacity that has been switched to the GFM operating mode, that is the total energy capacity ST_GFL multiplied by the parameter A.
111 1 110 11 12 112 116 11 12 For example, when the controllercalculates that the energy capacity S_GFM of the microgridat time t is larger than the load capacity S_Load required by each of the loads Nand N, a part of the inverter devices-is operating under the GFM operating mode to provide power to each of the loads Nand N.
In the method of the essential load capacity provided under the GFM operating mode determination, when the controller calculates that the energy capacity S_GFM is larger than the essential loads capacity SC_Load of the essential loads, one or multiple inverter devices are switched to the GFM operating mode, and is configured to provide power to the essential loads. The method of the essential load capacity provided under the GFM operating mode determination satisfies the following equation.
Specifically, when the energy capacity S_GFM of the microgrid at time t is larger than the essential loads capacity SC_Load, the energy capacity S_GFM of one or multiple inverter devices operating under the GFM operating mode can provide power to the essential loads in the microgrid. At this moment, the energy capacity S_GFL of the inverter devices operating under the GFL operating mode is equal to the total energy capacity ST_GFL subtracting the energy capacity that has been switched to the GFM operating mode, that is the total energy capacity ST_GFL multiplied by the parameter A.
11 12 111 1 110 11 112 116 112 116 11 12 11 11 11 11 12 For example, when the load Nis the essential load, the load Nis the non-essential load, and when the controllercalculates the energy capacity S_GFM of the microgridat time t is larger than the essential loads capacity SC_Load required by the load N, a part of the inverter devices-is switched to the GFM operating mode, and the other part of the inverter devices-is operating under the GFL operating mode to jointly provide power to the loads Nand N. In the example mentioned above, when the load capacity required by the load Nchanges, such as the load capacity increases, the inverter devices that are operating under the GFM operating mode are configured to output power according to the changed load capacity of the load N, so as to absorb the changes of the load capacity required the load N. At this moment, the inverter devices operating under the GFM operating mode and the GFL operating mode remain jointly providing power to the loads Nand N.
110 112 114 112 114 11 115 116 115 116 In some circumstances, when the microgridis operating, the inverter devices-operate under the GFM operating mode, the energy capacity of the inverter devices-is sufficient to cover the changes of the load capacity of the load N. Relatively, the inverter devices-operate under the GFL operating mode. At this moment, the inverter devices-are operating in the maximum power output to follow, or output powers according to the deployment of the inverter devices operating under the GFM operating mode.
110 112 114 11 115 116 11 112 116 11 12 In some other circumstances, when the microgridis operating, and the energy capacity of the inverter devices-operating under the GFM operating mode is not sufficient to cover the change of the load capacity of the load N, the inverter devices-can further be switched to the GFM operating mode to absorb the change of the load capacity of the load N. In the method of the essential load capacity provided under the GFM operating mode determination, the inverter devices-are jointly configured to provide power to each of the loads Nand N.
112 116 In some embodiments, whether the inverter devices, such as the inverter devices-, can be switched to the GFM operating mode is determined according to the actual functionality of the inverter devices.
In the method of the essential load capacity provided under the GFL and the GFM operating modes determination, when the controller calculates that the energy capacity S_GFM is smaller than the essential loads capacity SC_Load of the essential loads, yet the sum of each of the energy capacities S_GFM and S_GFL is larger than the essential loads capacity SC_Load of the essential loads, each of the inverter devices is switched to the GFM operating mode or the GFL operating mode to provide power to the essential loads. The method of the essential load capacity provided under the GFL and the GFM operating modes determination satisfies the following equation.
Specifically, when the sum of the energy capacities S_GFM and S_GFL of the microgrid is larger than the essential loads capacity SC_Load, each of the inverter devices is operating under the GFM operating mode and the GFL operating mode, and jointly provides power to the essential loads in the microgrid. At this moment, the energy capacity S_GFL of the inverter devices operating under the GFL operating mode is equal to the total energy capacity ST_GFL subtracting the energy capacity that has been switched to the GFM operating mode, that is the total energy capacity ST_GFL multiplied by the parameter A.
11 12 111 1 11 112 116 112 116 1 11 12 1 1 11 12 11 11 112 114 For example, when the load Nis the essential loads, the load Nis the non-essential loads, and when the controllercalculates that the energy capacity S_GFM of the microgrid at time t is smaller than the essential loads capacity SC_Load required by the load N, a part of the inverter devices-is operating under the GFM operating mode, the other part of the inverter devices-remains operating under the GFL operating mode to provide the energy capacity S_GFL and jointly provide power to the loads Nand N. In some embodiments, since the energy capacities S_GFM and S_GFL are just sufficient to provide electricity to the loads Nand N. At this moment, when the load capacity required by the essential loads Nchanges, the changes of the load capacity of the load Ncannot be absorbed by the inverter devices-.
11 112 114 112 114 110 In some circumstances, when the changes of the load capacity of the load Ncannot be absorbed by the inverter devices-operating under the GFM operating mode, and the inverter devices-cannot immediately adjust the output voltage according to the changes of the load capacity, a voltage imbalance may occur on the bus BS.
11 12 112 116 110 112 116 12 In some other circumstances, when the load capacity due to the changes of the loads Nand Nis larger than the energy capacity that the inverter devices-can provide, the microgridis also able to maintain providing power by the inverter devices-through shedding the non-essential load N. However, the present disclosure is not limited to the circumstances mentioned above.
110 210 110 210 200 309 308 In some embodiments, the determination methods mentioned above are provided only for some embodiments of the disclosed microgridsand, but the present disclosure is not limited to this. In various embodiments, the microgridsandcan still be able to control the operating mode of the inverter devices according to various determination methods. The electric power systemperforms the operationafter the operationis performed.
309 112 116 212 216 111 211 In the operation, each of the inverter devices-and-transmits multiple state parameters of which the inverter devices have been switched to GFM operating mode and GFL operating mode back to the controllersand.
112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 111 211 112 116 212 216 111 211 200 310 309 Specifically, the state parameters mentioned above include output voltages V-Vand V-V, active powers P-Pand P-P, reactive powers Q-Qand Q-Qand the operating modes corresponding to the inverter devices-and-. The inverter devices-and-transmit the corresponding output voltages V-Vand V-Vto the controllersand, respectively. The inverter devices-and-further transmit the corresponding operating mode respectively to the controllersand. The electric power systemperforms the operationafter the operationis performed.
310 111 211 112 116 212 216 In the operation, the controllersanddetermines whether the state parameters of the inverter devices-and-after switching the operating mode are the same as the commands.
111 112 116 112 116 112 116 112 116 212 216 211 212 216 212 216 Specifically, the controllerdetermines whether the voltage levels of the output voltages V-Vare equal to an output voltage level V_DEF, whether the active powers P-Pand the reactive powers Q-Qare the same as the commands, and whether the operating modes of the inverter devices-and-are the same as the commands. The controllerdetermines whether the voltage levels of the output voltages V-Vare equal to the output voltage level V_DEF, and the operating mode of the inverter devices-are the same as the commands.
111 211 112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 200 311 111 211 112 116 212 216 112 116 212 216 112 116 212 216 112 116 212 216 200 312 In some embodiments, when the controllersanddetermine the output voltages V-Vand V-V, the active powers P-Pand P-P, the reactive powers Q-Qand Q-Q, and the operating modes of the inverter devices-and-are the same as the commands, the electric power systemperforms the operation. When the controllersanddetermine the output voltages V-Vand V-V, the active powers P-Pand P-P, the reactive powers Q-Qand Q-Q, and the operating modes of the inverter devices-and-are not the same as the commands, the electric power systemperforms the operation.
111 112 307 111 112 112 112 112 111 112 112 111 112 112 For example, when the commands of which the controllertransmits to the inverter devicein the operationincludes the rated output voltage level V_DEF and the GFM operating mode, and the rated output voltage level V_DEF has 50 volts, the controllerdetermines whether the voltage level of the output voltages Vis equal to 50 volts, and whether the active powers Pand the reactive powers Qare equal to the values of the commands, and whether the inverter deviceis operating under the GFM operating mode. When the controllerdetermining the voltage level of the output voltages Vis equal to 50 volts, and the inverter deviceis operating under the GFM operating mode, the controllerdetermining the output voltages Vand the operating mode of the inverter deviceare the same as the commands.
111 112 112 111 112 Relatively, when the controllerdetermining the voltage level of the output voltages Vis not equal to 50 volts, and/or the inverter deviceis not operating under the GFM operating mode, the controllerdetermining the output voltages Vand/or the operating mode are not the same as the commands.
311 110 210 11 12 21 22 In the operation, the microgridsandare islanded operated, and provide power to the loads N, N, Nand N.
111 112 116 112 116 10 110 11 12 211 212 216 212 216 20 210 21 22 200 300 311 Specifically, when the controllerdetermining the output voltages V-Vand the operating mode of the inverter devices-are the same as the commands, the switch CBremains cut off, the microgridis configured to provide power to the loads Nand N. When the controllerdetermining the output voltages V-Vand the operating mode of the inverter devices-are the same as the commands, the switch CBremains cut off, and the microgridis configured to provide power to the loads Nand N. The electric power systemcompletes the operation methodafter the operationis performed.
312 112 116 212 216 In the operation, the inverter devices-and-perform a parametric compensation.
111 112 116 112 116 112 116 112 116 111 112 116 1 5 211 212 216 212 216 212 216 212 216 211 212 216 6 10 200 309 312 Specifically, when the controllerdetermining the output voltages V-V, the active powers P-P, the reactive powers Q-Q, and the operating mode of the inverter devices-are not the same as the commands, the controllertransmits the commands to the inverter devices-respectively through the signals S-Sonce again. When the controllerdetermining the output voltages V-V, the active powers P-P, the reactive powers Q-Q, and the operating mode of the inverter devices-are not the same as the commands, the controllertransmits the commands to the inverter devices-respectively through the signals S-Sonce again. The electric power systemrepeats the operationafter the operationis performed.
In some approaches, since the infrastructure of the utility power grid and the microgrid utilize the feeder cables for the microgrid to receive the power supply and as the power distribution path. The utility power grid usually provides electricity to the microgrid and the microgrid provides power to the loads. When power lines or the utility power grid at the upstream of the feeder cables is abnormal, the powers can only be supplied to the loads through the islanded microgrid at the downstream. Not until the abnormality is resolved did the utility power grid is reconnected to the microgrid. However, when the energy capacity that the islanded microgrid can provide is insufficient, the power demand of the loads can only be lowered by load shedding. The power supply in some emergencies or essential facilities may as a result be interrupted.
100 200 112 116 212 216 1 10 1 2 130 112 116 212 216 1 10 110 210 11 12 21 22 100 200 Compared to the approaches above, in the embodiments of the present disclosure, the electric power systemsandcan control the inverter devices-and-to switch the operating mode through the signals S-Simplemented by the GOOSE communication lines. When abnormalities occur to the lanes Land Lconnecting to the utility power grid, the inverter devices-and-are switched from the GFL operating mode to the GFM operating mode according to the signals S-S, such that the islanded microgridsandremains providing power to the loads N, N, Nand N. The disclosed electric power systemsandcan further prevent the emergencies or essential facilities from electricity shortage due to the abnormality of the utility power grid.
4 FIG. 4 FIG. 200 10 110 20 210 is a schematic diagram of the electric power system, illustrated in accordance with some embodiments of the present disclosure. As illustratively shown in, the switch CBin the microgridhas been cut off, and the switch CBin the microgridis thrown in.
4 FIG. 3 FIG. 4 FIG. 111 1 306 10 111 112 116 1 5 112 114 115 116 112 114 110 1 112 114 115 116 110 1 115 116 Referring toand, in the circumstances of the, the controllerdetermines that the lane Lis abnormal in the operation, ant cuts off the switch CB. At this moment, the controllertransmits the commands to the inverter devices-respectively through the signals S-Sto switch each of the inverter devices-to the GFM operating mode, and keeps each of the inverter devices-operate under the GFL operating mode. When the inverter devices-are operating under the GFM operating mode, the microgridhas the energy capacity S_GFM provided by the inverter devices-. When the inverter device-are operating under the GFL operating mode, the microgridhas the energy capacity S_GFL provided by the inverter devices-.
11 12 11 12 1 112 114 11 12 1 112 114 11 12 In some circumstances, when the load Nis the essential loads, and the load Nis the non-essential loads, the load Nhas the essential load capacity SC_Load, and the load Nhas the non-essential load capacity SNC_Load. At this moment, when the energy capacity S_GFM is larger than the load capacity S_Load, which is the sum of the essential loads capacity SC_Load and the non-essential loads capacity SNC_Load, the inverter devices-are configured to provide power to each of the loads Nand N. Specifically, the energy capacity S_GFM provided by the inverter devices-is provided to each of the loads Nand N.
1 112 114 115 116 11 12 112 114 11 112 114 1 110 11 112 116 11 12 11 112 114 11 In some embodiments, when the energy capacity S_GFM is larger than the essential loads capacity SC_Load, and is smaller than the load capacity S_Load, the inverter devices-operate under the GFM operating mode, the inverter devices-operate under the GFL operating mode to provide power to the loads Nand N. Wherein, the inverter devices-are configured to absorb the changes of the load capacity of the load N. Specifically, when the inverter devices-are operating under the GFM operating mode, the energy capacity S_GFM provided by the microgridis larger than the load capacity required by the load N. At this moment, the inverter devices-are jointly providing power to each of the loads Nand N. At this moment, when the load capacity of the load Nchanges, the inverter devices-can be configured to absorb the changes of the load capacity of the load N.
1 112 116 11 12 11 12 112 116 111 12 110 12 112 116 11 1 112 114 1 115 116 11 12 11 112 114 1 11 111 12 1 11 In some other embodiments, when the energy capacity S_GFM is smaller than the essential loads capacity SC_Load, each of the inverter devices-is configured to provide power to the loads Nand N. When the load capacity required by the changes of the loads Nand Nis larger than the energy capacity that the inverter devices-can provide, the voltage may abruptly drop. The controllercuts off the switch CBN, and the microgridstop providing power to the load N, such that the energy capacity generated by each of the inverter devices-is sufficient to be provided to the load N. Specifically, the energy capacity S_GFM provided by the inverter devices-operating under the GFM operating mode and the energy capacity S_GFL provided by the inverter device-operating under the GFL operating mode are configured to be provided to each of the loads Nand N. When the load capacity of the load Nchanges, the inverter devices-are unable to adjust the provided energy capacity S_GFM to absorb the changes of the load capacity of the load N. At this moment, the controllersheds the load N, such that the energy capacity S_GFM is sufficient to be provided to the essential loads N.
11 12 12 11 110 11 12 In some other circumstances, when the load Nis the non-essential loads, and the load Nis the essential loads, the load Nhas the essential loads capacity SC_Load, the load Nhas the non-essential loads capacity SNC_Load. At this moment, the operation of the microgridis similar to the previously mentioned circumstances, with only switching the load Nwith the load N. Therefore, the similarities are not repeated herein for simplicity.
4 FIG. 4 FIG. 4 FIG. 211 2 306 20 130 210 21 22 Referring toand, in the circumstances of, the controllerdetermining the lane Lis normal in the operation. At this moment, the switch CBremains thrown in, and the utility power gridkeeps providing electricity to the microgridso as to provide power to the loads Nand N.
5 FIG. 5 FIG. 200 10 110 20 210 is a schematic diagram of the electric power system, illustrated in accordance with some embodiments of the present disclosure. As illustratively shown in, each of the switch CBin the microgridand the switch CBin the microgridhas been cut off.
5 FIG. 3 FIG. 5 FIG. 111 1 306 10 211 2 20 Referring toand, in the circumstances of, the controllerdetermining the lane Lis abnormal in the operation, and cuts off the switch CB. The controllerdetermining the lane Lis abnormal, and cut off the switch CB.
111 112 116 1 5 112 114 115 116 211 212 216 6 10 212 214 215 216 At this moment, the controllertransmits the commands to the inverter devices-respectively through the signals S-Sto switch each of the inverter devices-to the GFM operating mode, and keeps each of the inverter devices-operating under the GFL operating mode. Relatively, the controllertransmits the commands to the inverter devices-respectively through the signals S-Sto switch each of the inverter devices-to the GFM operating mode, and keeps each of the inverter devices-operating under the GFL operating mode.
112 114 212 214 110 1 112 114 210 2 212 214 115 116 215 216 110 1 115 116 210 215 216 2 In some embodiments, when each of the inverter devices-and-remains operating under the GFM operating mode, the microgridhas the energy capacity S_GFM provided by the inverter devices-, and the microgridhas the energy capacity S_GFM provided by the inverter devices-. When each of the inverter devices-and-is operating under the GFL operating mode, the microgridhas the energy capacity S_GFL provided by the inverter device-, and the microgridhas the inverter device-the energy capacity S_GFL.
11 21 12 22 11 21 1 2 12 22 1 2 In some circumstances, when the loads Nand Nare the essential loads, and the loads Nand Nare the non-essential loads, the load Nand Nhave the essential loads capacities SC_Load and SC_Load respectively, the loads Nand Nhave the non-essential loads capacities SNC_Load and SNC_Load respectively.
1 1 1 1 112 114 11 12 1 112 114 11 12 2 2 2 2 212 214 21 22 2 212 214 21 22 At this moment, when the energy capacity S_GFM is larger than the load capacity S_Load, which is the sum of the essential loads capacity SC_Load and the non-essential loads capacity SNC_Load, the inverter devices-are configured to provide power to each of the loads Nand N. Specifically, the energy capacity S_GFM of the inverter devices-is configured to be provided to each of the loads Nand N. Relatively, when the energy capacity S_GFM is larger than the load capacity S_Load, which is the essential loads capacity SC_Load and the non-essential loads capacity SNC_Load, the inverter devices-are configured to provide power to each of the loads Nand N. Specifically, the energy capacity S_GFM of the inverter device-is configured to be provided to each of the loads Nand N.
1 1 1 112 114 115 116 11 12 1 112 114 1 115 116 11 12 11 112 114 11 2 2 2 212 214 215 216 21 22 2 212 214 2 215 216 21 22 21 212 214 21 In some embodiments, when the energy capacity S_GFM is larger than the essential loads capacity SC_Load, and is smaller than the load capacity S_Load, the inverter devices-operate under the GFM operating mode, and the inverter devices-operate under the GFL operating mode, and jointly provide power to the loads Nand N. Specifically, the energy capacity S_GFM of the inverter devices-and the energy capacity S_GFL of the inverter devices-are configured to jointly provide power to the loads Nand N. At this moment, when the energy capacity required by the load Nchanges, the inverter devices-operating under the GFM operating mode can further absorb the changes of the energy capacity required by the load N. Relatively, when the energy capacity S_GFM is larger than the essential load capacity SC_Load, and is smaller than the load capacity S_Load, the inverter devices-operate under the GFM operating mode, and the inverter devices-operate under the GFL operating mode to jointly provide power to the loads Nand N. Specifically, the energy capacity S_GFM of the inverter devices-and the energy capacity S_GFL of the inverter devices-are configured to jointly provide power to the loads Nand N. At this moment, when the energy capacity required by the loads Nchanges, the inverter device-operating under the GFM operating mode can further absorb the change of the energy capacity required by the loads N.
1 1 112 116 11 12 11 12 112 116 111 12 110 12 1 112 114 1 115 116 11 12 1 112 114 11 111 12 110 11 2 2 212 216 21 22 212 214 21 211 22 210 22 2 212 214 2 215 216 21 22 2 212 214 21 211 22 210 21 In some other embodiments, when the energy capacity S_GFM is smaller than the essential loads capacity SC_Load, each of the inverter devices-is configured to provide power to the loads Nand N. When the load capacity required by the changes of the loads Nand Nis larger than the energy capacity that the inverter devices-can provide, the voltage may abruptly drop. The controllercuts off the switch CBN, such that the microgridstop providing power to the load N. Specifically, the energy capacity S_GFM of the inverter devices-and the energy capacity S_GFL of the inverter device-are configured to be provided to the loads Nand N. When the energy capacity S_GFM of the inverter devices-is not sufficient to absorb the changes of the energy capacity required by the load N, the controllersheds the load N, such that the microgridmaintains providing power to the load N. Relatively, when the energy capacity S_GFM is smaller than the essential loads capacity SC_Load, each of the inverter devices-is configured to provide power to the loads Nand N. At this moment, the energy capacity of the inverter device-operating under the GFM operating mode are not sufficient to absorb the changes of the energy capacity of the load N, the controllercuts off the switch CBN, such that the microgridstop providing power to the load N. Specifically, the energy capacity S_GFM of the inverter devices-and the energy capacity S_GFL of the inverter devices-are configured to jointly provide power to the loads Nand N. When the energy capacity S_GFM of the inverter devices-is not sufficient to absorb the changes of the load capacity of the load N, the controllersheds the load N, such that the microgridmaintains providing power to the load N.
11 21 12 22 12 22 1 2 11 21 1 2 110 210 11 21 12 22 In some other circumstances, when the loads Nand Nare the non-essential loads and the loads Nand Nare the essential loads, the loads Nand Nhave the essential loads capacities SC_Load and SC_Load respectively, and the loads Nand Nhave the non-essential loads capacities SNC_Load and SNC_Load respectively. At this moment, the operation of the microgridsandis similar to the previously mentioned circumstances, with only switching the loads Nand Nwith the loads Nand N. Therefore, the similarities are not repeated herein for simplicity.
5 FIG. 4 FIG. 112 114 212 214 112 116 212 216 Referring toand, the present disclosure is not limited to switch the inverter devices-and-to the GFM operating mode. In various embodiments, each of the inverter devices-and-can be switched between the GFM operating mode and the GFL operating mode.
The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
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November 5, 2025
July 16, 2026
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